Dyadic International, Inc. announced successful top-line results for the Phase 1 clinical trial of its recombinant protein RBD vaccine candidate, DYAI-100. This marks the first-in-human use of a recombinant protein vaccine expressed by Dyadic's C1- cell expression platform. The Phase 1 clinical trial was a double-blind placebo-controlled safety study of 30 healthy adults conducted in collaboration with Dyadic's South Africa licensee Rubic One Health ("Rubic").

In late 2022, Dyadic received regulatory approval of its Clinical Trial Application (CTA) from the South African Health Products Regulatory Authority (SAPHRA) to conduct the Phase I clinical trial for an antigen produced using its C1-cell protein expression platform. The primary endpoint of the study was to demonstrate the safety and reactogenicity of recombinant proteins. The C1 SARS-CoV-2 RBD single booster vaccine was administered at two dose levels.

Top-line safety data confirmed that the study met its primary endpoint demonstrating that both dose levels are safe and well tolerated and that the vaccine produced immune responses at both dose levels.